Technical Abstract:
In 2006, propagative material accounted for $725 million (8.3%) of the total wholesale value for the nursery and floriculture industries nationwide. Despite a 10% increase in total value from 2003-2006, rising fuel and input costs have reduced profitability for producers. A key component of a propagation nursery is a quality substrate for root development, commonly peat moss or pine bark. Competition for pine bark resources and the increasing cost of peat has increased interest in alternative substrates. Recent research suggests processed whole pine trees can be utilized for growing a variety of nursery and floriculture crops. We evaluated root development of Salvia leucantha stem cuttings in pine bark (PB) and whole pine tree (WPT) substrates, with and without peat (P). Stem cuttings were inserted into substrates (PB, PB+P, WPT or WPT+P) and placed under intermittent mist in a greenhouse. At project termination, roots were washed, scanned for digital analysis and dried. Digital images of each root sample were analyzed for root length and root volume. On average, PB+P treatments contained the greatest root lengths, root volumes and dry weights, while WPT substrates had the lowest. The addition of peat increased root length by 4.5% and 26% in PB and WPT substrates, respectively. Root dry weight was 29% greater in PB+P compared to WPT+P. Although overall root development was lower in WPT substrates, the addition of peat enhanced development. In future experiments, we will investigate WPT particle size and nutrient inputs to potentially improve root development in WPT substrates.